Transport Scotland announced that the date for completing the temporary repair to the Woodside Viaducts and removing traffic management from the motorway’s eastbound carriageway is now scheduled for Autumn 2026, with the westbound carriageway scheduled for the second half of 2027.
Amey, undertaking work on behalf of Transport Scotland, is working to overcome previously unknown challenges at the site, coupled with ongoing work to control previously known risks.
These include the strengthening of the triangular crossheads which support the viaducts at their western end and the associated propping steelwork, both of which have been more complicated than anticipated.
However, Transport Scotland claims the need to avoid loading the SPT tunnels has introduced an unusual level of complexity and has resulted in delays to propping both the eastbound and westbound viaducts.
Meanwhile, most significantly, an existing sewer, adjacent to the SPT tunnel at the western end of the viaducts, was found to be in a different location than expected.
It is claimed that this has slowed progress to the temporary propping in this location and, despite mitigation measures already in place, is impacting the completion of the westbound viaduct propping.
The revised dates for completion of the works remain subject to no further adverse conditions or unforeseen challenges.
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Transport Scotland also confirmed the cost range for the project remains between £126m and £152m.
In May last year, we reported how the works could cost up to £71m more than planned after being delayed, as the Scottish Government revealed in 2023 estimated cost of the propping works was £81.6m.
(Image: Transport Scotland) The works, which started in 2021 and were to run until late 2024, were expected to be completed by early 2026.
However, the Scottish Government’s transport department said the contractor was working towards delivering the eastbound carriageway sooner, in Summer 2025, which has since been pushed back to Autumn 2026.
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Lawrence Shackman, Transport Scotland’s director of major projects, said: “I understand the completion of these works is keenly anticipated by M8 road users and the local community, not least to lessen the impacts from its construction.
“I’d like to thank everyone for their patience and understanding to date and assure them that Transport Scotland continues to robustly engage with the contractor, Amey, to deliver the work as quickly and safely as possible, whilst keeping the motorway open to the 150,000 vehicles that use it daily.
“Despite facing significant challenges, the project has made substantial progress with temporary props installed at 13 pier locations out of 23.
“In addition, 10 of the temporary props have been jacked to assist with supporting the carriageway and taking the load.
“The location of the motorway through a busy, built-up city has meant this project has always been technically complex and presented a number of challenges, notwithstanding dealing with 23 supports that all require individual propping designs to take account of the varying column heights, span lengths and widths.
“The project has been continuously hampered by inaccurate records of utility apparatus, as well as the recent discovery of an uncharted sewer buried deep underground, leading to delays and additional work.
“Amey continues to face significant challenges, and the latest information now indicates an anticipated date for full completion of the work, allowing traffic management to be removed in the second half of 2027.
“Due to the nature of the work, they are continuing to work towards opening the Eastbound carriageway in Autumn 2026.”
Ahead of planned refurbishment works on the road, investigations into the condition of the supports of each viaduct (crossheads) started in late 2020 and early 2021.
Engineers found that the supports of each viaduct were in worse condition than anticipated.
In March 2021, it was decided that it was necessary to prop up suspended spans for more extensive repairs to be done.
It meant lane closures and speed restrictions on the M8 were put in place, and roads underneath the viaduct were closed to allow work to be carried out from below.
